It's been 4 months now and I'm sitting with a vehicle that I now cannot use

Please note that I have purchased a vehicle in the month of June and I received excellent service from the sales rep . I cannot fault him with the service he had provided to me however the vehicle is another situation. I had many encounters which I had brought to his notice which he was and is trying to assist with me. I purchased the car in June, 2 and a half months later the battery keeps dying which I brought to his notice. He then told me that he will have to notify his manager which he then did. I have all my receipts and messages. I have been told that the company does not cover for batteries and its not their problem and this was in the first 3 months of me purchasing this vehicle. I have even gone to a battery center and they have confirmed it as well. I worked for a tracking company so I know how the dealerships work. And I know my right as a consumer. Please could someone superior look into this as I am taking it up further. I'm sitting with a vehicle that cannot start and it is the festive season and I have children. It was so embarrassing for the past 3 weeks to go to places and have to boost the battery in public.